Fluid operated web break detector assembly with switch actuator motion blocking means

ABSTRACT

In air-stream actuated web-break detectors an air-deflectable cup-like switch actuator is formed with a surrounding lip which shields the partially enclosed switch assembly from incursion of fiber and like particles otherwise tending to obstruct the switching function. In operation an air-stream is projected through an elongated tube having an orifice which faces the switch actuator. For disabling the detector for repair purposes, a single movable assembly slides a sleeve over the tube orifice to interrupt the air-stream and concurrently moves into place a part which blocks the motion of the switch actuator.

United States Patent [191 Larson July 9, 1974 1 FLUID OPERATED WEB BREAK 2,884,495 4/1959 Frankel ZOO/61.13 {DETECTOR ASSEMBLY WITH SWITCH 3,178,527 4/1965 Cooksey ZOO/61.13 X 3,309,474 3/1967 Heinrich ZOO/61.07

ACTUATOR MOTION BLOCKING MEANS Clifford L. Larson, Des Plaines, Ill.

Korthe Engineering Corporation, Schiller Park, Ill.

Filed: Aug. 20, 1973 Appl. No.: 389,889

Inventor:

Assignee:

[56] References Cited UNITED STATES PATENTS 2/1942 Hercik ZOO/61.18 7/1958 Scriver ZOO/61.07 UX Primary Examiner-James R. Scott Attorney, Agent, or Firm--St.Onge Mayers & Reens switch actuator. For disabling the detector for repair purposes, a'single movable assembly slides a sleeve over the tube orifice to interrupt the air-stream and I concurrently moves into place a part which blocks the motion of the switch actuator.

3 Claims, 5 Drawing Figures 7 mamas SHEET 1 0F 2 WW. \N/ Mb IILPRITHIWIIM HT| l l II I l| v 3% 5i i 3 PMENIEDJUL 919M gamma SHEEI 2 BF 2 I I j FLIJI @PETED WEB BREAK DETECTOR ASSEMBLY WITH STCI-ll ACTUATOR MOTION BLOCKING ANS BACKGROUND OF THE INVENTION This invention relates to improvements in web-break detectors and more particularly to improvements in the type of detector which, for its operation, depends upon the impingement of a directed air stream or the like upon a control element.

The air-stream actuated type of detector, as such, is known, being described, for example, in U.S. Pat. No. 3,178,527, granted Apr. 13, 1965 in the name of Otha Cooksey and in U.S. Pat. No. 2,405,552, granted Oct. 15, 1968 in the name of Thomas J. Luckett. In application Ser. No. 362,405, filed May 21, 1969 in the name of George W. Bregar, there is described a particular form of detector which combines a deflectable cup-like switch actuator having a surrounding protective lip with an air-stream providing tube having an orifice opposed to the actuator. The present invention is concerned with the provision of means usable in connection with a detector of the kind just described for concurrently interrupting the air stream and blocking motion of the switch actuator, all for the purpose of temporary disablement of the actuator, for example, during a period when normal functioning of the detector is not desired. To this end, the invention provides a single movable assembly, advantageously combined with the main structure of the detector, by which a barrier can be slid over the air orifice while at the same time a blocking part passes under the lip "of the deflectable actuator to prevent its downward displacement.

The more detailed aspects of the invention are specified in the following description taken in connection with the accompanying drawing. In the drawing:

FIG.- I is a side elevation of a preferred embodiment of the invention;

FIG. 2 is a top view of the embodiment of FIG. ll;

FIG. 3 is a section taken on line 33 of FIG. I;

FIG. 4 is a fragmentary break-away view of a segment of FIG. I; and

FIG. 5 is a view similar to FIG. 4., but showing some of the parts in an altered relationship.

FIG. I offers a side view of apparatus applying the present invention, such apparatus being shown in its intended working relationship with a web I0 (e-.g., I of paper or fabric) which is assumed to be moving either into or out of the plane of the paper. Only an edge portion of the web is shown, and the means employed for supporting and driving the web are not illustrated, being well-known in the art, as exemplified by Cooksey U.S. Pat. No. 3,178,527. The web-break detecting apparatus in connection with which the present invention is employed includes a base plate 115 by which the apparatus may be assumed to be mounted in the appropriate relationship to the surface of web III. Surmounting the base and attached to it by securing means 116 located near its extremities is a housing which, with the base plate, constitutes a substantially complete enclosure for a microswitch assembly of which the switch-containing component is indicated at 22. As is shown in FIG. 3, this assembly is supported laterally from the housing 20 by support members 24 and includes (FIG. 11) conventional external circuit connections 25 which are adapted for connection with an appropriate control system through an extended cable 27. The cable 27 in turn is supported by and carried through the end wall of the housing 2t) by means of a grommet 29.

The microswitch 22 is further provided with a movable actuating element (Le, a depressable rod) 30 which protrudes above its upper surface and which, when depressed, (depending upon whether the switch is designed to be of the normally on or normally off variety) opens or closes switch contacts contained within the switch housing 22. The element 30 is in its turn subject to actuation by a flexible spring arm which is supported in cantilever fashion at its right end by being attached to the upper surface of the switch enclosure 22, as indicated at 33. The working relationship between the actuating element 30 and the spring arm 35 is shown more clearly in FIG. 5, in which Figure it is apparent that when the spring arm 35 is in its uppermost or normal position it has no engagement with the element 30. On the other hand, when it is deflected into its activated position as indicated in dotted outline in FIG. 4, it engages the element 30 so as to depress that element and actuate the switching elements contained within the micro switch 22. Depending upon the nature of the control system employed, this actuation may serve either to open or close the associated switch contacts, but in either case the normal ef-v fect of actuation would be to de-energize the machinery driving the web III and to produce any other control action appropriate to shutting down the system as a whole so that repair operations might be undertaken.

As clearly appears in, FIGS. I and 2, the upper surface 20a of the enclosure 20 has near one end a circular opening 40 within which a cup-like member 411 is supported by attachment to the underlying extremity of the deflectable spring arm 35. Such attachment may, of course, be by brazing, by screw connection or otherwise. The function of the cup-like member 40 may best be understood by referring to the further apparatus part 42 which, as appears most clearly in FIGS. I and 2, is supported above it and has a center line that perpendicularly intersects the vertically projected center line of the member 40. The part 42 is a hollow elongated tube of metal or other structurally rigid material which is closed at the end nearest the cup-like member 40 by a cap 43, and which at its other end, is connected to a flexible tube 44 through which, in the intended use of the apparatus, it will be supplied with compressed air or other actuating fluid. The part is held in fixed relation to the enclosure 20 by means of a rigid bridging column 45 which extends between the two and which encloses in telescoping relation a slidable shaft 46 which terminates at its upper end in an exposed extension 46a. This extension in turn has a circular opening 46b which loosely engages the part 42 so that that part may be positioned in its desired relationship to the cuplike member 41. Moreover, the telescoping relationship of the shaft 46 and the surrounding column 45 permits the former to be moved up and down to a limited degree in order that the distance between the parts 41 and 42 can be varied to suit the conditions of use of the apparatus. Set-screws 47a and 47b are provided to lock the parts 42 and 46 in their preferred locations.

At a point directly above the center of the cup-like member 411 the tubular part 42 is provided with a small opening or orifice 50 through which compressed air (or other gaseous fluid receivedfrom the tube 44) can be t 3 directed against the upper surface of the web as suggested by the directed dash line 52. Under the conditions just postulated and as long as the web 10 is maintained intact and in normal tension in the position indiunder these conditions, the web will go slack and the impinging air stream 52 (as well as the force of gravity) will cause it to bear down upon the member 41 with resultant downward deflection of the spring arm 35. In either of these cases, the switch-actuating element 30 will be moved by the spring arm 35, and the control contacts of the microswitch 22 will be actuated with the result that the web-driving machinery will be shut down before damage to either the web or the machinery can occur.

By use of the invention of the previously mentioned application of George W. Bregar, the illustrated apparatus realizes a significant improvement over earlier constructions in its provision of more effective means for protecting the working elements of the switchactuating mechanism 22 from fouling or obstruction by dust, lint or fibrous particles. In many conditions of operation of the apparatus, such particles tend to be driven into the interior of the enclosure because of the continuous movement of the web 10 in close proximity to the opening 40. The illustrated construction largely overcomes this difficulty by providing in connection with the cup-like part 41 an annular outwardly extending lip 41a which overhangs the bounding edge of the opening 40. This lip partially shields the opening during normal web movement but, more importantly, engages in a closure shielding relationship the upper perimeter of the opening '40 M as most clearly shown in FIG. 4 when the member 41 is driven into its depressed or activated position, by impingement of the airstream 52 or by engagement with the web 10. The effect of this interaction between the lip 41 and the upper surface of the enclosure 20 is twofold. First, it prevents the cup from being depressed so far toward the interior of the enclosure that dust and lint may be swept over the edge of the cup into the enclosure and second, as clearly appears in FIG. 4, it tends to provide a partial seal around the periphery of the opening 40. The conjoint result of these effects is a significant extension of the period of reliable operation of the apparatus.

It will be noted also that the apparatus shown in the drawings includes, in addition to the features already described, a sleeve part 60 which is slidingly positioned on the outer surface of the tubular part 42 in such a way that it may be moved axially to cover the orifice 50 and thus shut off the air stream 52 for the purpose of temporarily disabling the web-break detection function. While this feature is not new in itself, it is, in accordance with the present invention, combined with additional structure in a novel and especially useful way. More specifically, by means of a bridging assembly shortly to be described, the sleeve 60 is coupled with a generally rectangular sliding member which rides on the upper surface of the enclosure 20 with its depending lips 70a overlapping the side walls of the enclosure. This member is attached to the enclosure by a pin 71 which passes through a slot 72 formed in the enclosure surface and which is held in the slot by an attached flexible and spring-like washer or plate 73 large enough to overlie the edges of the slot. Sufficient lateral flexibility is incorporated in the part 73 that the member 70 may be lifted slightly above the surface of the enclosure 20 against the resilient restraint which the part 73 provides.

In order that the sliding member 70 and the tubular sleeve 60, previously described, may be moved in unison, they are interconnected by a bridging assembly which includes, in the first instance, a tongue 75 which is integrally joined to the end of member 70 but turned to be perpendicular to it. The tongue 75 in turn is slidably engaged in telescoping fashion by a metal form 76 bent around it and terminating at its upper end (FIGS. 1 and 3) in a rounded end part 760. This is provided with a hole 76b of such size as snugly to engage the tubular sleeve 60, which is rigidly fixed in the hole, for example, by a combination of peening and brazing. The telescoping arrangement of the parts 75 and 76 permits the bridge which they jointly create between the slidable member 70 and the sleeve 60 to be maintained, whether the sleeve is in either the lower or the upper of the twopositions in which it is shown in FIG. 1. Accordingly, the bridge can be manually grasped to move it and with it the parts 60 and 70 to the left of the position shown in FIGS. 1 and 2, irrespective of the relative separation between these parts. As previously explained, such motion closes the air stream opening 50.

It next needs to be noted (by reference to FIG. 2) that the part 70 has a U-shaped cutout 70d which, as 70 is moved to the left (along with the sleeve 60), will embrace and engage the outer periphery of the part 41. It will readily be seen that when the part 70 is relocated to the left as just indicated, its terminal extensions 70b and 70c will underlie the lip 41a (see FIG. 5) in such fashion as tolimit downward deflection of the cup by any force which may be brought to bear upon its upper surfaces. This is with the object that microswitch 22 shall not be unintentionally activated while the apparatus is supposedly in disabled condition as the result of the movement of the tubular part 60 to the position in which it cuts off the air vent opening 50. Therefore, the sleeve 60 and the plate 70 conjointly provide means by which, upon their simultaneous displacement in the left hand direction, both the air stream 52 and the deflectable arm 35 can be concurrently disabled from performing their normally intended functions. The blocking effect of the part 70 is made still more positive in the arrangement of FIGS. 1 through 4 by providing on the upper surface 20a of the housing 20 a small protrusion or embossment 70 which operates as a camming means to lift the plate 70 as the plate moves to the left in such a way that its terminal parts 70b and 700 will more closely underlie the lip 41a of the cup-like member 41 as indicated in FIG. 5, thus reducing its range of possible downward movement to'a few millimeters.

While the invention has been described by reference to a particular embodiment, it will be understood that the following claims are intended to cover all variations and equivalents which fall within its true spirit and scope.

What I claim as new and desire to secure by Letters Patent is:

11. In an apparatus which is to be mounted in proximity to a moving web for detecting breaks and voids in the web, and which is of the type that includes:

A. an extended tubefor receiving pressurized fluid,

said tube having 1. a lateral orifice by which such fluid can be directed against one side of the web, and

2. an external part slidable along the tube so as either to cover the orifice or to leave it uncovered;

B. a control structureto be positioned in facing relation to, but on the opposite side of the web from said tube, said structure comprising 11. a deflectable part operable when deflected to actuate a switching element for stopping movement of the web,

2. a housing at least partially enclosing the deflectable part and having an opening directed toward the normal path of the web surfaces,

3. a cup-like member mounted on said deflectable part and movable when subjected to deflect the deflectable part, said member having a. its lateral wall portion projecting through said opening with the open face of the member directed toward the web path, and b. its open face at least partially surrounded by a peripherally extending lip which overhangs the edge of the opening; the improvement which comprises:

C. a movable member supported on the surface of said housing and slidable thereon to become interposed between said lip and the housing so as to block control-actuating motion of the cup-like member; and

D. means joining the said slidable part and the said movable member for sliding them concurrently so as simultaneously to cover the said orifice and block motion of the cup-like member.

2. The improvement of claim l in which the joining means comprises a bridging assembly constituted of mutually telescoping elements for maintaining joinder of the slidable part and the movable member while permitting variation in the relative separation between them.

3. The improvement of claim l in which a camming means provided on the surface of the housing that supports the said movable member serves to lift that member as it is slid into its blocking position, thereby causing it to closely underlie the lip of the cup-like member. 

1. In an apparatus which is to be mounted in proximity to a moving web for detecting breaks and voids in the web, and which is of the type that includes: A. an extended tube for receiving pressurized fluid, said tube having
 1. a lateral orifice by which such fluid can be directed against one side of the web, and
 2. an external part slidable along the tube so as either to cover the orifice or to leave it uncovered; B. a control structure to be positioned in facing relation to, but on the opposite side oF the web from said tube, said structure comprising
 1. a deflectable part operable when deflected to actuate a switching element for stopping movement of the web,
 2. a housing at least partially enclosing the deflectable part and having an opening directed toward the normal path of the web surfaces,
 3. a cup-like member mounted on said deflectable part and movable when subjected to deflect the deflectable part, said member having a. its lateral wall portion projecting through said opening with the open face of the member directed toward the web path, and b. its open face at least partially surrounded by a peripherally extending lip which overhangs the edge of the opening; the improvement which comprises: C. a movable member supported on the surface of said housing and slidable thereon to become interposed between said lip and the housing so as to block control-actuating motion of the cup-like member; and D. means joining the said slidable part and the said movable member for sliding them concurrently so as simultaneously to cover the said orifice and block motion of the cup-like member.
 2. an external part slidable along the tube so as either to cover the orifice or to leave it uncovered; B. a control structure to be positioned in facing relation to, but on the opposite side oF the web from said tube, said structure comprising
 2. a housing at least partially enclosing the deflectable part and having an opening directed toward the normal path of the web surfaces,
 2. The improvement of claim 1 in which the joining means comprises a bridging assembly constituted of mutually telescoping elements for maintaining joinder of the slidable part and the movable member while permitting variation in the relative separation between them.
 3. The improvement of claim 1 in which a camming means provided on the surface of the housing that supports the said movable member serves to lift that member as it is slid into its blocking position, thereby causing it to closely underlie the lip of the cup-like member.
 3. a cup-like member mounted on said deflectable part and movable when subjected to deflect the deflectable part, said member having a. its lateral wall portion projecting through said opening with the open face of the member directed toward the web path, and b. its open face at least partially surrounded by a peripherally extending lip which overhangs the edge of the opening; the improvement which comprises: C. a movable member supported on the surface of said housing and slidable thereon to become interposed between said lip and the housing so as to block control-actuating motion of the cup-like member; and D. means joining the said slidable part and the said movable member for sliding them concurrently so as simultaneously to cover the said orifice and block motion of the cup-like member. 